zephyr/drivers/gpio/gpio_mcp23s17.c

444 lines
10 KiB
C

/*
* Copyright (c) 2020 Geanix ApS
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT microchip_mcp23s17
/**
* @file Driver for MCP23S17 SPI-based GPIO driver.
*/
#include <errno.h>
#include <kernel.h>
#include <device.h>
#include <init.h>
#include <sys/byteorder.h>
#include <drivers/gpio.h>
#include <drivers/spi.h>
#include "gpio_utils.h"
#include "gpio_mcp23s17.h"
#define LOG_LEVEL CONFIG_GPIO_LOG_LEVEL
#include <logging/log.h>
LOG_MODULE_REGISTER(gpio_mcp23s17);
/**
* @brief Read both port 0 and port 1 registers of certain register function.
*
* Given the register in reg, read the pair of port 0 and port 1.
*
* @param dev Device struct of the MCP23S17.
* @param reg Register to read (the PORTA of the pair of registers).
* @param buf Buffer to read data into.
*
* @return 0 if successful, failed otherwise.
*/
static int read_port_regs(struct device *dev, u8_t reg, u16_t *buf)
{
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
int ret;
u16_t port_data;
u8_t addr = MCP23S17_ADDR | MCP23S17_READBIT;
u8_t buffer_tx[4] = { addr, reg, 0, 0 };
const struct spi_buf tx_buf = {
.buf = buffer_tx,
.len = 4,
};
const struct spi_buf_set tx = {
.buffers = &tx_buf,
.count = 1,
};
const struct spi_buf rx_buf[2] = {
{
.buf = NULL,
.len = 2
},
{
.buf = (u8_t *)&port_data,
.len = 2
}
};
const struct spi_buf_set rx = {
.buffers = rx_buf,
.count = ARRAY_SIZE(rx_buf),
};
ret = spi_transceive(drv_data->spi, &drv_data->spi_cfg, &tx, &rx);
if (ret) {
LOG_DBG("spi_transceive FAIL %d\n", ret);
return ret;
}
*buf = sys_le16_to_cpu(port_data);
LOG_DBG("MCP23S17: Read: REG[0x%X] = 0x%X, REG[0x%X] = 0x%X",
reg, (*buf & 0xFF), (reg + 1), (*buf >> 8));
return 0;
}
/**
* @brief Write both port 0 and port 1 registers of certain register function.
*
* Given the register in reg, write the pair of port 0 and port 1.
*
* @param dev Device struct of the MCP23S17.
* @param reg Register to write into (the PORTA of the pair of registers).
* @param buf Buffer to write data from.
*
* @return 0 if successful, failed otherwise.
*/
static int write_port_regs(struct device *dev, u8_t reg, u16_t value)
{
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
int ret;
u16_t port_data;
LOG_DBG("MCP23S17: Write: REG[0x%X] = 0x%X, REG[0x%X] = 0x%X",
reg, (value & 0xFF), (reg + 1), (value >> 8));
port_data = sys_cpu_to_le16(value);
u8_t addr = MCP23S17_ADDR;
u8_t buffer_tx[2] = { addr, reg };
const struct spi_buf tx_buf[2] = {
{
.buf = buffer_tx,
.len = 2,
},
{
.buf = (u8_t *)&port_data,
.len = 2,
}
};
const struct spi_buf_set tx = {
.buffers = tx_buf,
.count = ARRAY_SIZE(tx_buf),
};
ret = spi_write(drv_data->spi, &drv_data->spi_cfg, &tx);
if (ret) {
LOG_DBG("spi_write FAIL %d\n", ret);
return ret;
}
return 0;
}
/**
* @brief Setup the pin direction (input or output)
*
* @param dev Device struct of the MCP23S17
* @param pin The pin number
* @param flags Flags of pin or port
*
* @return 0 if successful, failed otherwise
*/
static int setup_pin_dir(struct device *dev, u32_t pin, int flags)
{
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
u16_t *dir = &drv_data->reg_cache.iodir;
u16_t *output = &drv_data->reg_cache.gpio;
int ret;
if ((flags & GPIO_OUTPUT) != 0U) {
if ((flags & GPIO_OUTPUT_INIT_HIGH) != 0U) {
*output |= BIT(pin);
} else if ((flags & GPIO_OUTPUT_INIT_LOW) != 0U) {
*output &= ~BIT(pin);
}
*dir &= ~BIT(pin);
} else {
*dir |= BIT(pin);
}
ret = write_port_regs(dev, REG_GPIO_PORTA, *output);
if (ret != 0) {
return ret;
}
ret = write_port_regs(dev, REG_IODIR_PORTA, *dir);
return ret;
}
/**
* @brief Setup the pin pull up/pull down status
*
* @param dev Device struct of the MCP23S17
* @param pin The pin number
* @param flags Flags of pin or port
*
* @return 0 if successful, failed otherwise
*/
static int setup_pin_pullupdown(struct device *dev, u32_t pin, int flags)
{
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
u16_t port;
int ret;
/* Setup pin pull up or pull down */
port = drv_data->reg_cache.gppu;
/* pull down == 0, pull up == 1 */
if ((flags & GPIO_PULL_DOWN) != 0U) {
return -ENOTSUP;
}
WRITE_BIT(port, pin, (flags & GPIO_PULL_UP) != 0U);
ret = write_port_regs(dev, REG_GPPU_PORTA, port);
if (ret == 0) {
drv_data->reg_cache.gppu = port;
}
return ret;
}
static int mcp23s17_config(struct device *dev,
gpio_pin_t pin, gpio_flags_t flags)
{
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
int ret;
/* Can't do SPI bus operations from an ISR */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
if ((flags & GPIO_OPEN_DRAIN) != 0U) {
ret = -ENOTSUP;
goto done;
};
ret = setup_pin_dir(dev, pin, flags);
if (ret) {
LOG_ERR("MCP23S17: error setting pin direction (%d)", ret);
goto done;
}
ret = setup_pin_pullupdown(dev, pin, flags);
if (ret) {
LOG_ERR("MCP23S17: error setting pin pull up/down (%d)", ret);
goto done;
}
done:
k_sem_give(&drv_data->lock);
return ret;
}
static int mcp23s17_port_get_raw(struct device *dev, u32_t *value)
{
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
u16_t buf;
int ret;
/* Can't do SPI bus operations from an ISR */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
ret = read_port_regs(dev, REG_GPIO_PORTA, &buf);
if (ret != 0) {
goto done;
}
*value = buf;
done:
k_sem_give(&drv_data->lock);
return ret;
}
static int mcp23s17_port_set_masked_raw(struct device *dev,
u32_t mask, u32_t value)
{
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
u16_t buf;
int ret;
/* Can't do SPI bus operations from an ISR */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
buf = drv_data->reg_cache.gpio;
buf = (buf & ~mask) | (mask & value);
ret = write_port_regs(dev, REG_GPIO_PORTA, buf);
if (ret == 0) {
drv_data->reg_cache.gpio = buf;
}
k_sem_give(&drv_data->lock);
return ret;
}
static int mcp23s17_port_set_bits_raw(struct device *dev, u32_t mask)
{
return mcp23s17_port_set_masked_raw(dev, mask, mask);
}
static int mcp23s17_port_clear_bits_raw(struct device *dev, u32_t mask)
{
return mcp23s17_port_set_masked_raw(dev, mask, 0);
}
static int mcp23s17_port_toggle_bits(struct device *dev, u32_t mask)
{
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
u16_t buf;
int ret;
/* Can't do SPI bus operations from an ISR */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
buf = drv_data->reg_cache.gpio;
buf ^= mask;
ret = write_port_regs(dev, REG_GPIO_PORTA, buf);
if (ret == 0) {
drv_data->reg_cache.gpio = buf;
}
k_sem_give(&drv_data->lock);
return ret;
}
static int mcp23s17_pin_interrupt_configure(struct device *dev,
gpio_pin_t pin,
enum gpio_int_mode mode,
enum gpio_int_trig trig)
{
return -ENOTSUP;
}
static const struct gpio_driver_api api_table = {
.pin_configure = mcp23s17_config,
.port_get_raw = mcp23s17_port_get_raw,
.port_set_masked_raw = mcp23s17_port_set_masked_raw,
.port_set_bits_raw = mcp23s17_port_set_bits_raw,
.port_clear_bits_raw = mcp23s17_port_clear_bits_raw,
.port_toggle_bits = mcp23s17_port_toggle_bits,
.pin_interrupt_configure = mcp23s17_pin_interrupt_configure,
};
/**
* @brief Initialization function of MCP23S17
*
* @param dev Device struct
* @return 0 if successful, failed otherwise.
*/
static int mcp23s17_init(struct device *dev)
{
const struct mcp23s17_config *const config =
dev->config_info;
struct mcp23s17_drv_data *const drv_data =
(struct mcp23s17_drv_data *const)dev->driver_data;
drv_data->spi = device_get_binding((char *)config->spi_dev_name);
if (!drv_data->spi) {
LOG_DBG("Unable to get SPI device");
return -ENODEV;
}
if (config->cs_dev) {
/* handle SPI CS thru GPIO if it is the case */
drv_data->mcp23s17_cs_ctrl.gpio_dev =
device_get_binding(config->cs_dev);
if (!drv_data->mcp23s17_cs_ctrl.gpio_dev) {
LOG_ERR("Unable to get GPIO SPI CS device");
return -ENODEV;
}
drv_data->mcp23s17_cs_ctrl.gpio_pin = config->cs_pin;
drv_data->mcp23s17_cs_ctrl.delay = 0;
drv_data->spi_cfg.cs = &drv_data->mcp23s17_cs_ctrl;
LOG_DBG("SPI GPIO CS configured on %s:%u",
config->cs_dev, config->cs_pin);
}
drv_data->spi_cfg.frequency = config->freq;
drv_data->spi_cfg.operation = (SPI_OP_MODE_MASTER | SPI_MODE_CPOL |
SPI_MODE_CPHA | SPI_WORD_SET(8) |
SPI_LINES_SINGLE);
drv_data->spi_cfg.slave = config->slave;
k_sem_init(&drv_data->lock, 1, 1);
return 0;
}
#define MCP23S17_INIT(inst) \
static struct mcp23s17_config mcp23s17_##inst##_config = { \
.common = { \
.port_pin_mask = \
GPIO_PORT_PIN_MASK_FROM_DT_INST(inst), \
}, \
.spi_dev_name = DT_INST_BUS_LABEL(inst), \
.slave = DT_INST_REG_ADDR(inst), \
.freq = DT_INST_PROP(inst, spi_max_frequency), \
\
IF_ENABLED(DT_INST_SPI_DEV_HAS_CS_GPIOS(inst), \
(.cs_dev = \
DT_INST_SPI_DEV_CS_GPIOS_LABEL(inst),)) \
IF_ENABLED(DT_INST_SPI_DEV_HAS_CS_GPIOS(inst), \
(.cs_pin = \
DT_INST_SPI_DEV_CS_GPIOS_PIN(inst),)) \
}; \
\
static struct mcp23s17_drv_data mcp23s17_##inst##_drvdata = { \
/* Default for registers according to datasheet */ \
.reg_cache.iodir = 0xFFFF, \
.reg_cache.ipol = 0x0, \
.reg_cache.gpinten = 0x0, \
.reg_cache.defval = 0x0, \
.reg_cache.intcon = 0x0, \
.reg_cache.iocon = 0x0, \
.reg_cache.gppu = 0x0, \
.reg_cache.intf = 0x0, \
.reg_cache.intcap = 0x0, \
.reg_cache.gpio = 0x0, \
.reg_cache.olat = 0x0, \
}; \
\
/* This has to init after SPI master */ \
DEVICE_AND_API_INIT(mcp23s17_##inst, DT_INST_LABEL(inst), \
mcp23s17_init, &mcp23s17_##inst##_drvdata, \
&mcp23s17_##inst##_config, \
POST_KERNEL, \
CONFIG_GPIO_MCP23S17_INIT_PRIORITY, \
&api_table);
DT_INST_FOREACH_STATUS_OKAY(MCP23S17_INIT)